Lapping machine for the production of reinforcement baskets with bell sleeve

ABSTRACT

A lapping machine for the production of reinforcement baskets with a bell sleeve for concrete pipes and the like, which comprises longitudinal rods and an armament wire wound about the longitudinal rod. Two synchronously driven driver disks for holding and guiding, respectively, are provided. One of the disks is longitudinally displaceable in a machine frame and support the ends of the longitudinal rods. The other of the disks is immovable and axially guides the longitudinal rods. Radially adjustable guide means are pivotally connected to radial arms of a central holding disk. The arms extend along a conical jacket, so that an axial movement of the holding disk results in a simultaneus radial displacement of the guide means for the longitudinal rods and means are arranged for controlling the axial movement of the holding disk in dependency upon the path of the supporting disk.

United States Patent 91 Pfender 51 Feb. 27, 1973 [54] LAPPING MACHINE FOR THE 3,275,785 9/1966 Wilson ..219/56 PRODUCTION OF REINFORCEMENT ,BASKETS WITH BELL SLEEVE Inventor: Georg Pfender, Kisslegg, Germany Firma Wehrle-Werk AG., Emmendingen, Germany Filed: Feb. 22, 1971 Appl. No.: 117,320

Assignee:

Foreign Application Priority Data Feb. 21, 1970 Germany ..P 20 08 095.9 Feb. 21, 1970 Germany ..P 20 08 094.8 March 26, 1970 Germany ..P 20 14 719.7

References Cited UNITED STATES PATENTS 9/1933 Halkyard et al. ..219/56 5/1966 Olivier et al ..219/56 Primary ExaminerJ. V. Truhe Assistant Examiner-L. A. Schutzman AttorneyErnest G. Montague [57] ABSTRACT A lapping machine for the production of reinforce ment baskets with a bell sleeve for concrete pipes and the like, which comprises longitudinal rods and an armament wire wound about the longitudinal rod. Two synchronously driven driver disks for holding and guiding, respectively, are provided. One of the disks is longitudinally displaceable in a machine frame and support the ends of the longitudinal rods. The other of the disks is immovable and axially guides the longitudinal rods. Radially adjustable guide means are pivotally connected to radial arms of a central holding disk. The arms extend along a conical jacket, so that an axial movement of the holding disk results in a simultaneus radial displacement of the guide means for the longitudinal rods and means are arranged for controlling the axial movement of the holding disk in dependency upon the path of the supporting disk.

13 Claims, 6 Drawing Figures LAPPING MACHINE FOR THE PRODUCTION OF REINFORCEMENT BASKETS WITH BELL SLEEVE The present invention relates to a lapping machine for the production of reinforcement baskets with a bell sleeve for concrete pipes and the like, whereby the armature wire is wound about on longitudinal rods and is welded therewith and consists of two synchronously drivable coupling disks for holding and guiding the longitudinal rod, one of said disks holds the ends of the longitudinal rod, depending upon the type of the support, mounted for longitudinal movement in the machine frame, while the other inmovable disk guides the longitudinal rods which are axially displaceable.

Such machine still has the draw-back that only the cylindrical part of the armature basket can be wound by a machine, and that the bell sleeve determined for the connection of the concrete pipes and arming in a complicated method, respectively, must be produced mostly outside of the machine winding program.

In this type of production of the sleeve arming not only are additional structural parts required, but first of all time-and labor-requirement for the additional equipment and change of equipment of the machine is increased to create a draw-back.

It is one object of the present invention to provide a lapping machine for the production of reinforcement baskets with bell sleeve which avoids the draw-backs of the known structures.

It is another object of the present invention to provide a lapping machine for the production of reinforcement baskets with a bell sleeve, wherein the radially adjustable guides for the longitudinal rod in the immovable driving disk are pivotally connected with the radial arms of a central holding disk, whereby the arms run in accordance with a cone jacket, so that an axial movement of the holding disk results in a radial displacement of the guide for the longitudinal rods and whereby the axial holding disk movement is controllable in dependency upon the path of the supporting disk.

By this arrangement the longitudinal rods can be inserted into the machine without prefabrication and the sleeve armature can be produced, without interrupting the production and resetting the machine, so that the working output of the machine is increased.

The control of the apparatus, designed in accordance with the present invention, is obtained in dependency upon the longitudinal displacement of the supporting disk such that the holding disk at the end side is secured at the end of a central axially displacable shaft which at its end is rotatably mounted in a sleeve which has two diametrical cross bolts which penetrate in one arm of a forked lever, the other arm of which is pivotally connected to a guide rod, which is displaceable in longitudinal direction by means of a control body connected with a bearing block of the supporting disk. By this arrangement, in accordance with the present invention, as a control body there is provided a run-up face inclined towards the horizontal and following in horizontal direction, which run-up face moves up over the horizontal aim of an angular lever upwardly and downwardly, respectively, the vertical arm of which is pivoted to the guide rod.

By the proposed means it is possible to produce in one working step the arming basket with a bell sleeve, whereby the measurements of a sleeve armature, in particular the diameter, can be predetermined by corresponding forming of the control body and of the inclined run-up path, respectively.

Furthermore in accordance with the present invention the end of the run-up horizontal arm is equipped with a running roller, which is arranged as to its weight, such that it causes during downward movement a return position of the guide rod and thereby of the holding disk. Also this automatically operating device serves in an advantageous manner for a rational working procedure of the machine.

Furthermore the present invention deals with the formation of an automatically operated welding device for connection of the armature wire with the longitudinal rods in particular within the range of the bell sleeve.

This welding device is, in accordance with the present invention, disposed on a carrying frame displaceable radially to the armature basket, which carrying frame is equipped with a sensing member, which cooperates with the control edge in the sense of a radial displacement of the carrying frame, and which control edge is provided on a side rod displaceable parallel to the machine axle, whereby the movement of the guide rod is controllable in dependency upon the path of the supporting disk such, that the radial adjustment of the carrying frame during the forming of the bell sleeve takes place during the forming of the bell sleeve and corresponding to the diameter enlargement of the bell sleeve.

By such arrangement, the welding device adjusts itself, during the production of the larger diameter of the sleeve basket, automatically to the changed positions of the welding stations, so that the production of the armature basket with a bell sleeve is assured without interruption, and the working output of the machine is increased.

In a further development of the present invention an additional proposal is made, according to which a clamping angle is provided on the supporting disk for the longitudinal rod, which clamping angle jointly with a horizontal rail forms a tongue-like holding member, the opening and closing movement of which is brought about by means of a piston by pressure means, whereby for all pressure cylinders a joint pressure means control is provided.

In accordance with the present invention rod magazines oriented starlike about the medium longitudinal axis of the machine are disposed, from which rod magazines, the longitudinal rods are guided through the immovable, yet rotating, guide disk and are connected with the corresponding clamping angles.

By this arrangement a time consuming clamping and releasing of each individual longitudinal rod is avoided, whereby it is simultaneously assured that a sufficient holding effect in the rod holding members is present.

Furthermore, a certain storage of longitudinal rods is available in the machine so that the rods, after removing of a finished armature basket, are pulled only a short length from the magazine and fed into the guides of the immovable driving disk, and must be clamped rigidly and jointly in the holding means of the supporting disks.

With these and other objects which will become apparent in the following detailed description, the present invention, which is shown by example only, will be clearly understood in connection with the accompanying drawings, in which:

FIG. 1 is a side elevation of the entire machine, designed in accordance with the present invention;

FIG. 2 is a front elevation of the machine with the welding means;

FIG. 3 is a reduced schematic top plan view of the welding means;

FIG. 4 is a fragmentary elevation of another embodiment of the machine;

FIG. 5 is a schematic elevation of a holding element shown in FIG. 4 and indicated at an enlarged scale; and

FIG. 6 is a fragmentary section of a portion shown in FIG. 4 at an enlarged scale;

Referring now to the drawings, disks 2 and 3 are rotatably mounted on the machine frame 1 and are driven by conventional means, for instance, by means of a chain drive. The immovable disk 2 is guided in rollers 4, while the supporting disk 3 is mounted in a bearing 5, which is carried by a bearing block L, which is equipped with rollers 6, which support themselves on bottom rails 7, so that the block L with the disk 3 is reciprocable in a longitudinal direction.

The longitudinal rods 8 of the armature basket to be produced are secured in the supporting disk 3 by means of holding means 9 and are guided horizontally displaceably in guide 10 of the disk 2. The rods 8 are removed from magazines 11, the structure and function, however, are not part of the present invention and for this reason are not more closely disclosed.

v The guides 10 for the longitudinal rods are radially adjustable and pivotally connected to radial arms 12, which are pivotally connected with a central holding disk 13. For a better demonstration, only those parts 8, 10 and 12 disposed in the plane of the drawing are shown, which are arranged in reality corresponding with the number of the longitudinal rods used for the armature basket on a pitch circle about the median longitudinal axis.

The holding disk 13 is secured at the end side to a shaft 15, which passes through a hollow shaft 16 and is mounted with its end in a sleeve 17. The hollow shaft 16 is mounted in a bearing 18 and serves to guide the driver disk 2.

The sleeve 17 is equipped with two diametrical cross bolts ll9,--which penetrate into the upper arm 20 of a forked lever, which is pivotally mounted on the bearing block 21. The lower arm 22 is pivotally connected with the guide shaft 23, which is pivotally connected with an angular lever 24, which in turn is swingably mounted in a carrier 25 about the axle 26 and carries on its upper horizontal arm, a sensing roller 27.

On the longitudinal immovable bearing block L is disposed a control body ST, which has a run-up face 28 inclined towards the horizontal and a horizontal face 29. The control body ST is movable jointly with the bearing 5 and the supporting disk 3, respectively, in longitudinal direction.

The operation of the shown machine is as follows:

The machine is shown in an operative state, in which the armature basket is about one third finished. By a welding device 30, the winding wire 14 is welded with the longitudinal rods 8. Since the welding process and Since in the winding processes the supporting disk 3 with the longitudinal rods 8 are moved in the direction of the arrow P, at the end of the cylindrical part of the armature basket, the control body ST with its inclined 'run-up face 28 runs below the sensing roller 27 with the lever 24, so that these parts are lifted up into the position shown in point dotted lines. By this arrangement the guide rod 23 is moved towards the left and simultaneously the forked lever 20 and 22 swings about its rotary point D. By this movement the sleeve 17 is displaced towards the right, whereby the shaft 15 and the holding disk 13 are likewise displaced towards the right, so that the radial arms 12 radially outwardly displace the longitudinal rod guides 10 on the disk 2. This displacement causes a bending of the longitudinal rod 8, which in this operational state already have left the magazine 11. By this arrangement the desired bellshaped diameter widening is created at the end of the armature basket, which on the machine, or after removal of the basket, can be wound completely by hand.

During equipping a machine for a new winding process, the supporting disk 3 is again brought into its starting position. The sensing roller moves thereby by its own weight again downwardly and sets by means of the rods 23, the lever 20 and 22 and the shaft 15 also the holding disk 13 with the levers l2 and the guides 10, back into their original position.

In the machine in accordance with FIGS. 2 and 3, the immovable rotating driver disk 2 is equipped with a central holding disk 13, which is pivotally connected by radial arms 12 with the guides 10 for the longitudinal arms 8. These guides 10 are radially displaceable into the spokes 35 of the driver disk 2 and comprise the guide rollers 36 and 37, as well as the six-faced welding cams 38, which serve as welding support for the longitudinal rods 8. These welding cams 38 are rotatable and fixable to the fork-like arms 12, so that they can be rotated for changing the prevailing engagement face, when the latter became nonusable by wear.

The welding device, equipped for the resistance welding, comprises substantially two co-axial welding rollers of which only the front roller 40 can be seen. Both rollers are connected with the current conduit 41' which are connected with the transformer 42.

While the non-visible welding roller during rotation of the disk in the direction of the arrow P provides a contact with the longitudinal rod 8 to be welded, the roller 40 performs the actual welding between the winding wire 14 and the longitudinal rod 8. The former is set in a wire guide 43 and reaches, by means of guide rollers 44, to a position between the welding roller 40, equipped with a groove, and the longitudinal rod 8, whereby the latter is supported on the face of the welding cam 38.

For the cooling, the welding rollers run through water containers 46, which are provided with cooling water by means of conduits 47.

Each welding roller is mounted on a swinging lever 48 which is swingably mounted on the frame part 49 about the pivot point 50. The other end of the lever 48 is anchored by means of a full spring 51 on a frame 49, whereby the tension of its spring is variable for the setting of the engagement pressure of the roller 40 by means of screws 52.

The frame part 49, which carries the welding device is part of the block frame 53 which sits displaceably on profile rods 54. By means, not particularly shown, the box frame 53 can be adjusted radially to the drive disk 2, so that prior to the start of the winding process, the welding device can be set to the diameter of the armature basket to be produced.

The rods 54 form the upper closure of a welding carriage 55, which is likewise formed box-like and has at its bottom-part rollers 56, which are guided on profile rods 57 extending cross to the longitudinal axis of the machine, so that the welding carriage likewise is movable radially to the driver disk 2.

This movement serves the automatic adjustment of the welding device on the enlarged diameter of the armature basket for the bell sleeve and is caused by the guide rod 23 by means of an inclined control edge 58, on which a sensing roller 59 of the carriage 55 engages.

The movement of the rod 23 depends upon the longitudinal movement of the armature basket during the winding process, whereby the guide rod performs a movement towards the left (FIG. 2), as soon as the transfer from the cylindrical part of the basket to the bell sleeve starts. This movement can simultaneously cause an axial adjustment of the holding disk 13 in the direction towards driver disk 2, so that a deformation of the longitudinal rods 8 outwardly takes place by means of the arms 12, until the new enlarged diameter of the armature for the bell sleeve is obtained. In the same measure, the welding carriage 55 is moved thereby backwardly by the control edge 58, so that the welding of the winding wire up to the completion of the complete armature basket is assured without interruption.

The driver disks 2 and 3 are rotatably mounted in the machine frame 1 and are synchronously driven in any manner (not shown), for example by means of a chain drive. The immovable disk 2 is guided in rollers 4 and mounted in a bearing 61 by means of a shaft 60. The supporting disk 3 is mounted in a bearing 5, which is carried by a bearing block L, which is equipped with rollers 6, which support themselves on bottom rails 7, so that the disk 3 can reciprocate in the longitudinal direction.

For securing of the longitudinal rods 8 in the supporting disk 3, radially adjustable end fixable holding devices (FIG. 2 are provided which comprise a clamping angle 63 and a horizontal rail 64, on which the clamping angle 63 is pivoted swingably thereabout on axle 65. The clamping angle which is equipped with clamping jaws 66 forms with the rail 64, a tongue-like holding device, into which the longitudinal rod 8 can slide and be rigidly clamped. The rigid clamping is made by a pneumatic pressure cylinder 67, which is secured to the rail 64 and the piston rod 68 of which is pivoted to the clamping angle 63.

On each spoke 69 of the supporting disk 3 there is provided a holding device 62, which is set corresponding to the diameter of the armature basket to be produced and which can be secured by screws 70.

' These holding devices can be operated after insertion of the rods 8, by a common central device, by pressure means in the direction of the closing and opening,

respectively, whereby the securing of the rods 8 and the release of the finished wound basket can be performed singly and fast.

A further simplification results during the equipment of the machine, such, that rod magazines 71 (FIG. 6) are provided for the storage of the longitudinal rods. The rod magazines 71 comprise rectangular tubes and are radially adjustable at the spokes 72 of the holding wheels 73 and 74, and are fixably arranged by screws 75. Notches 76 are provided on the spokes 72, the distances a of which are stepped up corresponding to the basket diameters to be produced.

The rod magazines 71 extend along the shaft 60 and are provided, in front of the bearing 61 to this shaft by the pivots 77, outwardly swingably. Since the magazines are formed correspondingly long, a sufficiently large radial adjustment range results, without bending the rods to a great extent during their transfer into the horizontal position and into the immovable driver disk 2, respectively. I

The welding of the longitudinal rods 8 with winding wire 14 takes place by a welding device 78. Since the welding process and the welding device are not part of the present invention, a more detailed description thereof can be omitted.

It should still be mentioned that for the sake of clarity only those parts 8, 62, 71 and 77 disposed in the plane of the drawing sheet are shown in FIG. 6. These parts correspond with the number of the longitudinal rods used for the armature basket on a pitch circle about the median longitudinal axis.

While I have disclosed several embodiments of the present invention, it is to be understood that these embodiments are given by example only and not in a limiting sense.

I claim:

1. A lapping machine for the production of reinforcement baskets with a bell sleeve for concrete pipes and the like, having longitudinal rods and circumferential wire wound about said rods, comprising a machine frame,

shafts mounted on said machine frame and extending parallel to said machine frame constituting a longitudinal direction of said machine frame,

two synchronously driven disks coaxially disposed on said shafts, respectively, for holding and guiding, respectively, said longitudinal rods,

means for rotatably driving said disks,

said machine frame including rails parallel to the axes of said shafts,

a bearing including a bearing block having rollers displaceably mounted on said rails,

an outer one of said disks being mounted in said bearing and longitudinally displaceable relative to said machine frame and supporting the ends of said longitudinal rods, and constituting a supporting disk,

the other of said disks constituting an inner disk being immovable and guiding, axially, said longitudinal rods,

an axially displaceable central holding disk, coaxially disposed relative to said inner disk,

arms extending from said central holding disk in a substantially radially inclined direction with respect to the axis of said shaft on which said inner disk is disposed,

radially adjustable longitudinal rod guide means for said longitudinal rods disposed on said inner disk being pivotally connected to said arms of said central holding disk, and

means for controlling the axial movement of said holding disk in dependency upon the axial movement of said supporting disk. 2. The lapping machine, as set forth in claim 1, which includes a central, axially displaceable shaft securing said holding disk on its end face at one end of said shaft, a sleeve rotatably mounting the other end of said shaft, said sleeve has two diametrical cross bolts, a forked lever having two arms, said cross bolts entering into one of said arms, a guide rod pivotally connected with the other of said arms, a control body displaceable in said longitudinal direction, a support disk supported by said bearing block, and 7 said control body is connected with said bearing block. 3. The lapping machine, as set forth in claim 2, wherein said control body comprises a run-up path inclined toward the horizontal and thereafter a horizontal path, an angle-lever having a horizontal arm and a vertical arm, said run-up path moving upwardly and downwardly said horizontal arm, and said vertical arm is pivoted to said guide rod. 4. The lapping machine, as set forth in claim 3, wherein the end of said horizontal arm has a roller, said roller is disposed as to its weight that it causes during its an upward movement a return movement of said guide rod andthereby of said central holding disk. 5. The lapping machine, as set forth in claim 1, which includes a carrying frame radially displaceable relative to said shafts, a welding device disposed on said carrying frame, said carrying frame is equipped with a sensing member, a control edge provided on said guide rod displaceable parallel to said longitudinal direction, said sensing member cooperates with said control edge in the sense of a radial adjustment. 6. The lapping machine, as set forth in claim 5, wherein said carrying frame comprises box-like carrying members to which said welding device, secured, said carrying member is equipped with profiled rollers which run on carrying member rails secured to the machine frame. 7. The lapping machine, as set forth in claim 5,

. wherein said welding device has two rollers in an isoaxle arrangement, to constitute electrodes, one of said rollers operating as a contact roller for the longitudinal rods, the other of said rollers operating as a welding roller, a six-faced welding cam adapted as welding support for said longitudinal rods, and said welding cam is disposed rotatably and fixedly on said arm of said central holding disk. 8. The lapping machine, as set forth in claim 5, which a joint pressure control means for pressure cylinders receiving said pistons. 10. The lapping machine, as set forth in claim 9, which includes rod magazines disposed and rotating star-like relative I to said longitudinal direction, and said longitudinal rods are fed through the immovable, but rotating guide disk and connected with the corresponding clamping angle. 11. The lapping machine, as set forth in claim 10, wherein said rod magazines comprise rectangular pipes and are radially swingably pivoted at the end of said shaft of said inner disk, holding wheels, and said rod magazines are radially fixed to spokes of at least one of said holding wheels disposed on said guide tube in the vicinity of said inner disk. 12. The lapping machine, as set forth in claim 11, wherein each of the spokes of said holding wheel has notches, serving as markers for the setting of said rod magazines, and the distances between said notches are stepped up corresponding with the basket diameters to be produced. 13. The lapping machine, as set forth in claim 12, which comprises two coaxial of said holding wheels engaging each other for holding said rod magazines, said holding wheels including hubs and said spokes,

and said spokes are set off relative to each other for a half division.

I 0' k 1F I 

1. A lapping machine for the production of reinforcement baskets with a bell sleeve for concrete pipes and the like, having longitudinal rods and circumferential wire wound about said rods, comprising a machine frame, shafts mounted on said machine frame anD extending parallel to said machine frame constituting a longitudinal direction of said machine frame, two synchronously driven disks coaxially disposed on said shafts, respectively, for holding and guiding, respectively, said longitudinal rods, means for rotatably driving said disks, said machine frame including rails parallel to the axes of said shafts, a bearing including a bearing block having rollers displaceably mounted on said rails, an outer one of said disks being mounted in said bearing and longitudinally displaceable relative to said machine frame and supporting the ends of said longitudinal rods, and constituting a supporting disk, the other of said disks constituting an inner disk being immovable and guiding, axially, said longitudinal rods, an axially displaceable central holding disk, coaxially disposed relative to said inner disk, arms extending from said central holding disk in a substantially radially inclined direction with respect to the axis of said shaft on which said inner disk is disposed, radially adjustable longitudinal rod guide means for said longitudinal rods disposed on said inner disk being pivotally connected to said arms of said central holding disk, and means for controlling the axial movement of said holding disk in dependency upon the axial movement of said supporting disk.
 2. The lapping machine, as set forth in claim 1, which includes a central, axially displaceable shaft securing said holding disk on its end face at one end of said shaft, a sleeve rotatably mounting the other end of said shaft, said sleeve has two diametrical cross bolts, a forked lever having two arms, said cross bolts entering into one of said arms, a guide rod pivotally connected with the other of said arms, a control body displaceable in said longitudinal direction, a support disk supported by said bearing block, and said control body is connected with said bearing block.
 3. The lapping machine, as set forth in claim 2, wherein said control body comprises a run-up path inclined toward the horizontal and thereafter a horizontal path, an angle-lever having a horizontal arm and a vertical arm, said run-up path moving upwardly and downwardly said horizontal arm, and said vertical arm is pivoted to said guide rod.
 4. The lapping machine, as set forth in claim 3, wherein the end of said horizontal arm has a roller, said roller is disposed as to its weight that it causes during its an upward movement a return movement of said guide rod and thereby of said central holding disk.
 5. The lapping machine, as set forth in claim 1, which includes a carrying frame radially displaceable relative to said shafts, a welding device disposed on said carrying frame, said carrying frame is equipped with a sensing member, a control edge provided on said guide rod displaceable parallel to said longitudinal direction, said sensing member cooperates with said control edge in the sense of a radial adjustment.
 6. The lapping machine, as set forth in claim 5, wherein said carrying frame comprises box-like carrying members to which said welding device, secured, said carrying member is equipped with profiled rollers which run on carrying member rails secured to the machine frame.
 7. The lapping machine, as set forth in claim 5, wherein said welding device has two rollers in an isoaxle arrangement, to constitute electrodes, one of said rollers operating as a contact roller for the longitudinal rods, the other of said rollers operating as a welding roller, a six-faced welding cam adapted as welding support for said longitudinal rods, and said welding cam is disposed rotatably and fixedly on said arm of said central holding disk.
 8. The lapping machine, as set forth in claim 5, which includes a welding carriage, and said carrying frame is radially adjustable on said welding carriage indePendently of the adjustment by said control edge relative to said shafts.
 9. The lapping machine, as set forth in claim 1, which includes a horizontal rail a clamping angle provided on said supporting disk for each of said longitudinal rods, to form jointly with said horizontal rail a tongue-like holding means, pressure means including a piston for opening and closing said holding means, and a joint pressure control means for pressure cylinders receiving said pistons.
 10. The lapping machine, as set forth in claim 9, which includes rod magazines disposed and rotating star-like relative to said longitudinal direction, and said longitudinal rods are fed through the immovable, but rotating guide disk and connected with the corresponding clamping angle.
 11. The lapping machine, as set forth in claim 10, wherein said rod magazines comprise rectangular pipes and are radially swingably pivoted at the end of said shaft of said inner disk, holding wheels, and said rod magazines are radially fixed to spokes of at least one of said holding wheels disposed on said guide tube in the vicinity of said inner disk.
 12. The lapping machine, as set forth in claim 11, wherein each of the spokes of said holding wheel has notches, serving as markers for the setting of said rod magazines, and the distances between said notches are stepped up corresponding with the basket diameters to be produced.
 13. The lapping machine, as set forth in claim 12, which comprises two coaxial of said holding wheels engaging each other for holding said rod magazines, said holding wheels including hubs and said spokes, and said spokes are set off relative to each other for a half division. 